Housing for a Component of an Exhaust System

ABSTRACT

The invention relates to a housing for a component of an exhaust system, comprising first ( 12 ) and second half-shells which are connected to each other at least in sections by means of an edge section ( 20 ), and an opening ( 18 ) for a pipe ( 22 ) which is to be connected to the housing ( 10 ), characterized in that the edge sections ( 20 ) run out at the opening ( 18 ) and the width of the edge sections ( 20 ) is reduced towards the opening ( 18 ). The invention further relates to a housing of this type comprising a pipe ( 22 ) fitted thereto, which is welded to the housing ( 10 ) by means of a weld seam ( 24 ), the width of the edge sections ( 20 ) in the region of the opening ( 18 ) being, at a maximum, equal to the height of the weld seam ( 24 ).

The present invention relates to a housing for a component of an exhaust system, comprising first and second half-shells which are connected to each other at least in sections by means of an edge section, and at least one opening for a pipe which is to be connected to the housing.

Housings of this type are in practical use and are employed for various components of the exhaust system, such as, e.g., for catalytic converters, diesel particulate filters, and especially for mufflers.

FIG. 1 shows, by way of example, a muffler 1 having a prior art housing 10 of the type initially mentioned. The housing 10 comprises a first half-shell 12 and a second half-shell, not shown in the Figure, disposed thereover. Arranged inside the housing 10 is an inner pipe 14 which, in some applications, is surrounded by an insulating mat 16 and which is adapted for partial insertion into it of an exhaust gas carrying pipe. The exhaust gas carrying pipe is connected to the housing 10 by means of an opening 18 which is arranged in the housing 10 in the region of an end face S.

The two half-shells have two lengthwise edge sections 20 that are connected to each other, e.g. by crimping or welding. This connection of the two half-shells is produced by a machine along the longitudinal edges of the two edge sections 20. The edge sections 20 have a substantially uniform width of about 8 to 10 mm over their entire length (in the case of a welded housing). Where seamed housings are involved, the edge section is made wider in most cases.

A drawback in the prior art housing 10 as described resides in that in the region of the opening 18, the housing 10 has a distinctly greater stiffness in the horizontal direction (i.e. along the edge sections 20) than in the vertical direction (perpendicular to the plane of the edge sections 20). This results in an abrupt change in stiffness in this region, which leads to a limited fatigue strength upon exposure to bending stresses and, hence, to a reduced durability of the housing.

In addition, the connection of the two half-shells along the longitudinal sides L of the housing 10 can only be produced by a machine without any difficulty up to a respective point P. This means that in the housing 10 according to the prior art, the two edges X on the end face, which are difficult to access when using a machine, of the edge sections 20 of the half-shells may have to be re-welded manually in order to close the housing 10 completely. Such a production step is comparatively complicated and therefore expensive.

The object of the present invention is therefore to provide a housing for a component of an exhaust system in which any sudden changes in stiffness are avoided in the region of an opening that serves for fitting an exhaust pipe, and which, furthermore, is simple to produce.

According to the invention, provision is made for this purpose in a housing of the type initially mentioned that the edge sections run out at the opening and the width of the edge sections is reduced towards the opening. In this way, the stiffness in the horizontal direction can be distinctly reduced and thus approximated to the stiffness in the vertical direction. This results in an increase in the fatigue strength of the housing in the region of the opening by about 30 percent and, hence, in a markedly improved durability that is comparable with the durability of a housing that includes an additional bracing in the region of the opening. In addition, in the design according to the invention, a manual re-welding process may in most cases be dispensed with.

To ensure an improved fatigue strength while the half-shells are at the same time securely connected together, the width of the edge sections in the region of the opening may amount to about half the regular width of the edge sections; advantageously, it amounts to about one third of the regular width.

Preferably, the housing has at least one pipe fitted thereto, which is welded to the housing by means of a weld seam, the width of the edge sections in the region of the opening being, at a maximum, equal to the height of the weld seam. Such a configuration results not only in the improved fatigue strength already described above, but, moreover, an involved and expensive manual re-welding of the edges on the end face of the edge sections can also be dispensed with. This means that the half-shells are connected to each other on the end face of the housing exclusively by the weld seam which is required in any case for fitting the exhaust gas carrying pipe, as a result of which a complete closure of the housing is realized in a simple, cost-effective and time-saving manner. In addition, the housing according to the invention is less susceptible to crack formation in the region of the weld seam.

A particularly favorable horizontal-to-vertical stiffness ratio, which results in an optimum fatigue strength of the housing in the region of the opening, is obtained if the edge sections include an angle of approximately 30 degrees with the center axis of the pipe.

Further features and advantages of the invention will become apparent from the description below of several preferred embodiments with reference to the accompanying drawings, in which:

FIG. 1 shows a partial sectional view of a muffler having a housing according to the prior art;

FIG. 2 shows a partial sectional view of a muffler having a housing according to a first embodiment of the invention;

FIG. 3 shows a partial sectional view of a muffler having a housing with a pipe fitted to it, according to the first embodiment of the invention;

FIG. 4 shows a second muffler housing according to the prior art; and

FIG. 5 shows a muffler housing according to a second embodiment of the invention.

FIG. 2 shows a housing 10 according to the invention, of a muffler 1, the housing replacing the housing 10 according to the prior art as illustrated in FIG. 1. In this connection, like components are provided with like reference numerals, and only the differences of the housing 10 according to the invention over that of the prior art will be discussed in the following. As can be seen in FIG. 2, in the case of the housing 10, the edge sections 20 run out at the opening 18 and the width of the edge sections 20 is reduced towards the opening 18. In this region the width of the edge sections 20 on the end face S is selected to amount to about half, or better, one third of the regular width of the edge sections, that is, approximately 2 to 4 mm. By designing the edge sections 20 in this way, a distinctly lower stiffness can be achieved in the horizontal direction, which results in an increase in the fatigue strength of the housing 10 in the region of the opening 18 by about 30 percent.

A further advantage of the housing 10 according to the invention will become obvious if an exhaust gas carrying pipe 22 is fitted to the housing 10 and welded to the housing 10 by means of a weld seam 24 (FIG. 3). Here, the weld seam 24, just like the opening 18, has essentially the shape of the pipe cross-section. Owing to the reduced width of the edge sections 20 in the region of the opening 18 into which the pipe 22 is inserted, the whole of the end-face regions X of both edge sections 20 can be closed at the same time by means of the weld seam 24, without the necessity of separately re-welding the housing 10 in the end-face region S thereof.

An optimum fatigue strength of the housing 10 can be obtained in that the edge sections 20 in the region of the opening 18 include an angle α of approximately 30 degrees with the center axis of the pipe 22.

FIG. 5 shows a second embodiment of the housing 30 according to the invention, which provides two separate flow paths 32 and is made use of as a housing of a center muffler, for example.

The housing 30 also consists of a first half-shell (not shown) and a second half-shell 34 disposed thereover, the lengthwise edge sections 36 of which are connected to each other, as has already been described above with reference to FIGS. 1 to 3.

A comparison with a housing 30 of a center muffler according to the prior art, which is illustrated in FIG. 4, will show that the edge sections 36 in the housing 30 according to the invention (FIG. 5) again run out at the two openings 38 and that their width is reduced towards the openings 38. In this second embodiment of the invention, too, the angle which the edge sections 36 include with the center axis of a pipe adapted to be inserted into the respective opening 38 amounts to approximately 30 degrees. In this way, in the housing 30 as well, a markedly improved fatigue strength is achieved over the prior art. 

1.-5. (canceled)
 6. A housing for a component of an exhaust system, comprising: first and second half-shells which are connected to each other by an edge section, and at least one opening for a pipe which is to be connected to the housing, wherein the edge section runs out at the opening and the width of the edge section is reduced towards the opening.
 7. The housing according to claim 6, wherein the width of the edge section in the region of the opening amounts to about half the regular width of the edge section.
 8. The housing according to claim 6, wherein the width of the edge section in the region of the opening amounts to about one third of the regular width of the edge section.
 9. The housing according to claim 1, further comprising at least one pipe fitted thereto, which is welded to the housing by a weld seam, the width of the edge section in the region of the opening being, at a maximum, equal to the height of the weld seam.
 10. The housing according to claim 1, wherein the edge section defines an angle of approximately 30 degrees with the center axis of the pipe. 